U.S. Pat. No. 5,205,395 Bruno et al., which is incorporated herein by this reference, discloses a vibratory movement apparatus particularly adapted to transportation, orientation, sorting and loading of miniature electronic components. In such an apparatus, reciprocating movements are imparted upon a platen carrying the components in one or two horizontal directions and a vertical direction. Solenoids are used to vibrate the independently translatable carriages supporting the platen in cooperation with returning springs. In such an apparatus, the resonance frequencies of the driving mechanism, particularly the springs, create harmonic resonance problems that significantly reduce the range of frequencies at which the platen can be made to vibrate. Moreover, the mass of the moving components introduces substantial inertia that also affects the usable range of frequencies and the response time of the mechanism.
Vibration tables have been used to minimize the tedious tasks of manually sorting and processing small electronic components such as capacitors and resistors. As disclosed in the referenced patent, a platen has a planar upper surface upon which the components to be sorted are allowed to randomly travel. The platen has bores, shaped and dimensioned to only accept components in one direction, typically longitudinally. Once all the bores in the platen have been filled, the components remaining on the top surface are removed. The components can then be processed while on the platen, or they can be pushed through the platen into a multi-cavity receiving matrix made of resilient material that can hold the components while they are dipped into an electrically conductive solution to create terminals upon the exposed part of the components or for other applicable processes.
Heretofore, the removal of the platen from the vibration table, the transfer to the multi-cavity matrix and most of the subsequent processing steps have been done manually. So have been the processes of placing the components upon the platen and collecting the excess components.
The excess inertia and resonance susceptibility of the prior art sorting equipment have imposed several restrictions upon the manipulation of parts such as the ability to impart upon the part complex multidirectional or circuitous travel paths, weight or density-based separation, consistent reorientation and other movements which require more complex variations in the frequency amplitude and phase relationship of the vibrating impulses.
The instant invention results from attempts to resolve the aforesaid problems in prior art transporting and sorting equipment and to reduce or suppress some of the manipulative tests involved in the manufacture of electronic parts.